1. Field of the Invention
The present invention relates to an information processing apparatus, an information processing system, an information input apparatus, an information input system and an information exchange method. In particular, it relates to a connection of an image input apparatus such as an electronic camera and an image processing apparatus.
2. Description of the Related Art
Some electronic cameras such as digital still cameras are capable of taking photographs while connected to a computer. When a photographing operation is performed with such an electronic camera, the image data obtained through the photographing operation are recorded in a flash memory (volatile memory) internally provided in the electronic camera and are also output to the computer.
The image data output from the electronic camera to the computer are displayed on a display device of the computer.
However, there is a problem in that when attempting a continuous shooting operation in the electronic camera connected to the computer, a significant length of time is required to write the image data into the nonvolatile memory in the electronic camera to result in poor operability due to long intervals elapsing during the continuous shooting operation. In addition, when recording the image data that have been transferred to the computer in a recording device such as a hard disk drive (HDD), the user needs to repeatedly set the drive name, the folder name, the file name and the like for each set of image data and save it.
In the prior art, image data output to a computer from an electronic camera connected to the computer are processed under default processing conditions and are displayed on the display device. If the user finds the image satisfactory he saves the corresponding image data in the hard disk or the like. If, on the other hand, the user decides that the image the display needs to be improved, he changes the processing conditions by adjusting the gradation, adjusting the tone, applying an unsharp mask filter or the like and then saves the data.
However, when sequentially outputting a plurality of images from the electronic camera, the user must go to a great deal of trouble and spend a great deal of time to process and save all the image data output from the electronic camera, as explained below.
After the user saves image data obtained by changing the processing conditions while a given image is displayed on the display, the next set of image data input from the electronic camera is processed under the default processing conditions and is displayed on the display.
For instance, if the photographing conditions are relatively constant, as in studio photography, it is likely that similar processing conditions will be required for a plurality of images obtained through a photographing operation. However, since the processing is implemented under the default processing conditions each time a new set of image data is output, as described above, the user must change the processing conditions every time a new set of image data is input to the computer. As a result, it takes a great deal of time to process and save all the image data output from the electronic camera.
In addition, there are electronic cameras that correct image data by utilizing a look-up table for gradation adjustment (hereafter in this specification, a look-up table is referred to as an “LUT”) in order to correct the contrast of image data obtained through photographing. Such an LUT for gradation adjustment is a data table that is referenced in order to ascertain a corrected gradation value corresponding to the gradation value of the image data yet to undergo the adjustment processing.
There are also electronic cameras that allow the contents of the LUT for gradation adjustment to be varied. Such an electronic camera must be connected to a computer when changing the contents of the LUT. A so-called tone curve is displayed on the computer screen to enable the user to set the gradation adjustment characteristics. The user modifies the tone curve to a desired shape by using a mouse or the like. The computer generates an LUT for the gradation adjustment in conformance to the tone curve created as described above, i.e., in conformance to the characteristics curve to be used for the gradation adjustment. This LUT is output from the computer to the electronic camera and is saved in the nonvolatile memory in the electronic camera. Thus, the gradation characteristics of images obtained through a photographing operation performed in the electronic camera can be modified according to user preference.
However, when changing the gradation conversion characteristics of the LUT saved in the electronic camera, it is sometimes difficult to change them as desired for the following reason.
Under normal circumstances, a tone curve is generated by the user plotting a plurality of points (normally several points) on an orthogonal coordinate system through a mouse operation or the like with the plurality of points then interpolated in conformance to a spline curve. Namely, a spline function is generated that expresses a curve passing through the plurality of points, i.e., control points, and the shape of the tone curve is defined by the function. The LUT, which is created based upon the tone curve, is a data table that is referenced in order to ascertain the value of corrected image data corresponding to the value (gradation value) of image data yet to undergo the adjustment processing. For instance, in conjunction with image data with 8-bit gradation, a data table constituted of 256 sets of data corresponding to the 0th gradation through the 255th gradation is saved in the electronic camera.
When changing the gradation conversion characteristics of the LUT saved in the electronic camera, the LUT data saved in the electronic camera are input to the computer and these input data are altered. By displaying the LUT data plotted on the orthogonal coordinate system described above, the gradation conversion characteristics of the LUT saved in the electronic camera can be visualized. However, the data displayed in this manner are obtained by plotting points based upon the 256 sets of data and interpolating these points. In other words, since the information regarding the control points mentioned above is lost, the number and positions of the points (control points) set by the user on the coordinates mentioned above to generate the original tone curve cannot be ascertained. It is extremely difficult to determine the number and positions of these control points from the LUT data.
For the reason explained above, the shape of the new tone curve obtained by the user engaged in an operation to change the shape of the tone curve generated based upon the LUT data read out from the electronic camera may be very different from what the user would expect.